The present invention relates to a rewritable multilayered disc having a write protection (recording/erasing prohibition) function and to an information recording/reproducing device for such a rewritable multilayered disc.
A floppy disc is known well as one of representative examples of rewritable discs having portability. The floppy disc has a write protection mechanism. A user can use the write protection mechanism to give a write protection to a floppy disc and cancel such write protection.
For example, in the case of selling a floppy disc storing commercial software or in the case of providing someone with a floppy disc storing important data, a write protection is given to the floppy disc. As a result, it is possible to prevent the commercial software or the important data stored in the floppy disc from being erased by mistake.
Whether or not a write protection is given to the floppy disc is identified not by an application program which utilizes a disc drive device, but by firmware which operates the disc drive device.
The rewritable discs having portability are often stored in a cartridge. The principal purpose of this is to protect the disc from external factors (e.g., dust, finger prints, etc.) which may damage the quality of the disc. Conventionally, when the rewritable disc having portability is stored in a cartridge, the write protection mechanism is provided to the cartridge.
However, in the case of a disc which is removable from the cartridge, e.g., a DVD-RAM, the disc removed from the cartridge may not be properly put back in the cartridge. In such a case, the write protection for the disc may not be implemented using the write protection mechanism provided to the cartridge.
The present invention is made in consideration of the problem described above, and an objective thereof is to proved a rewritable multilayered disc having a write protection function and an information recording/reproducing device for the rewritable multilayered disc.
In one aspect of the present invention, there is provided a rewritable multilayered disc having a plurality of recording layers in which at least one of the plurality of the recording layers has a layer information region for recording layer information which includes recording prohibition information, and the recording prohibition information indicates whether or not user data is prohibited from being recorded in a specific recording layer among the plurality of the recording layers.
In one embodiment of the invention, only a single recording layer among the plurality of the recording layers may have the layer information region.
In one embodiment of the invention, each of the plurality of the recording layers may have the layer information region.
In one embodiment of the invention, the layer information may include plurality pieces of recording prohibition information, and each of the plurality pieces of the recording prohibition information may indicate whether or not user data is prohibited from being recorded in a corresponding recording layer of the plurality of the recording layers.
In one embodiment of the invention, the layer information may further include authentication information for authenticating an entity having authority to rewrite the recording prohibition information.
In another aspect of the present invention, there is provided an information recording/reproducing device for a rewritable multilayered disc including a plurality of recording layers in which at least one of the plurality of the recording layers has a layer information region in which layer information including a recording prohibition condition indicating whether or not user data is prohibited from being recorded in a specific layer among the plurality of the recording layers is recorded, and the information recording/reproducing device includes: a layer information reproduction section for reproducing the layer information recorded in the layer information region; and a write protection section for determining whether or not user data is prohibited from being recorded in the specific recording layer based on the layer information and deciding whether or not the user data should be recorded in the specific recording layer based on the determination result.